The present invention is related to roadway barriers and safety systems, and more particularly, to cable guardrail systems.
Along many roadways it may be hazardous for a vehicle to leave the roadway. As a result, safety barriers, including guardrail systems, are used along roadways. The guardrail systems may act to contain and redirect an errant vehicle along such roadways. Such guardrail systems may dissipate some of the vehicle's energy. One such guardrail system is a cable guardrail system. Cable guardrail systems may reduce the damage caused to impacting vehicles and the injury to vehicle passengers. Compared with W-beam and three beam guardrail systems, cable guardrail systems are often more aesthetically appealing and may increase motorist sight distance. Cable guardrail systems also may reduce snow accumulation on adjacent highways and roadways.
A cable guardrail system in the past may have included a plurality of cables secured to a plurality of support posts. Various types of cables and wire ropes have been satisfactorily used for cable guardrail systems. Support posts have been made of wood, metal, or a combination of both. Additionally, cable guardrail systems have included cable anchors that fixed the end of the cables to the ground to maintain tension in the cables. Various types of anchor systems have been used including releasable anchors as described in U.S. Pat. No. 6,065,738 to Pearce.
The number of cables in prior cable guardrail systems has varied depending on factors such as the types of vehicles using the roadway and the types of hazards requiring the guardrail system. Cables have been attached to support posts using various attachment mechanisms. Some attachment mechanisms, such as hook-bolts, were used to attach a single cable to a support post. Another prior attachment mechanism attached three cables to one side of a support post as shown in U.S. Pat. Nos. 7,398,960 and 7,364,137 to Neusch. Other cable guardrail systems positioned cables on opposite sides of the support posts in order to protect against impact from either side such as might occur when the system was installed in a highway median.
The state of the art in cable guardrail systems has been documented and applied through specifications used by the industry. The United States Department of Transportation Federal Highway Administration provides “Standard Specifications for Construction of Roads and Bridges on Federal Highway Projects,” including a section for cable guardrail systems and attachment mechanisms. Industry groups such as the American Association of State Highway and Transportation Officials (AASHTO), the Associated General Contractors (AGC) of America, and the American Road & Transportation Builders Association (ARTBA) have developed “A Guide to Standardized Highway Barrier Hardware” that included specifications for cable guardrails and posts. These specifications teach a cable guardrail system having a cable attached by hook-bolts and nuts to one side of a flanged-channel post. Additionally, agencies in both the United States and Europe have established guidelines for impact testing of safety barrier systems.
Prior cable guardrail systems had several drawbacks. Some cable attachments were difficult or costly to manufacture and install. Installation of cable guardrail systems exposes installation personnel to risks associated with working on or near active highways and roadways. Cable guardrail systems have been developed that reduce installation time thereby reducing the risk faced by installation personnel. There continues to be a need, however, for cable guardrail systems that reduce installation time and cost, and reduce risk to personnel.
A hanger for a cable guardrail system capable of supporting at least two cables traverse a post is presently disclosed to dissipate a portion of an impacting vehicle's energy and enable an impacting vehicle to be redirected by the system. The cable guardrail system may be installed adjacent a roadway, such as along median strips, roadway shoulders, or any other path that is likely to encounter vehicular traffic.
The disclosed hanger comprises a first portion having first and second seats each capable of supporting a cable, with the first and second seats on opposite sides of a post, and a second portion capable of engaging the end of the post.
Additionally, the disclosed cable guardrail system may comprise a plurality of posts capable of supporting at least two cables traverse the posts, a plurality of hangers attached to at least a portion of the plurality of posts, and at least two cables supported by the first and second seats on opposite sides of the posts.